I use to use a product called dynaflow on high pressure copper to steel tubeing when I did HVAC/R work.MAPP gas can be used on small jobs.Dynaflow® | The Harris Products Group
I think it melts at 1600 and flows at 1650F.

"Silver bearing solder" is a tin based solder with some silver mixed in for extra strength, like 4-5%. Suitable for jewelry and light metal work. If a solder has a flux core, you don't need a separate flux. Something to permanently attach a bbl extension, for example, is more than 50% silver and is more a braze than a solder. Only ever seen it as a solid, no flux core. I use Stay Silv flux with it.

tanvil
from what I was reading on "the New Mapp"gas is real similar to ox/acly welding ... grab a few steel coat hangers/ wire ...no flux w/steel to steel needed and blend some steel parts together.You can also heat up cast iron while electric welding and then temper/ anneal during cool down with it all while electric welding . there are hard coatings ...powders ...that you can heat/cook on surfaces to hard face also.hell fill up some balloons (outside )fuze lots of uses n go boom

tanvil
from what I was reading on "the New Mapp"gas is real similar to ox/acly welding ... grab a few steel coat hangers/ wire ...no flux w/steel to steel needed and blend some steel parts together.You can also heat up cast iron while electric welding and then temper/ anneal during cool down with it all while electric welding . there are hard coatings ...powders ...that you can heat/cook on surfaces to hard face also.hell fill up some balloons (outside )fuze lots of uses n go boom

Ok I have to admit i am thick when it comes to this stuff so you are say that new mapp gas can be used like a regular welder to meld steel??? by using coat hangers, I remember years ago ( many moons ago) they talked about using coat hanger to weld sten tubes but i did not recall Mapp gas in the conversation I also remember they used brazing
this has not be discussed in the thread, what do folks here know about brazing??

Ok I have to admit i am thick when it comes to this stuff so you are say that new mapp gas can be used like a regular welder to meld steel???

Ummmmmm..NO.

Mapp gas does not have the heat to actually melt metal...Well maybe something REAL THIN but in the REAL world it's best for soldering..
A real oxy accetelyne set up will melt steel because you use the oxygen as a accelerant and you just can't do that with a Mapp gas torch.
Take this from a REAL welder.